Defect reduction using pad conditioner cleaning

ABSTRACT

A device for cleaning a pad conditioner that comprises a cleaning agent supply for providing a cleaning agent for cleaning a pad conditioner including a conditioning surface, a pad including an abrasive surface, and a pump rotating the pad with respect to the pad conditioner for rubbing the abrasive surface of the pad against the conditioning surface of the pad conditioner.

FIELD OF THE INVENTION

This invention relates in general to semiconductor wafer planarization and, more particularly, to chemical mechanical polishing (“CMP”) using a polishing pad conditioner and a cleaning device and a method thereof.

BACKGROUND OF THE INVENTION

Chemical mechanical polishing (“CMP”) is generally used to planarize semiconductor wafers or remove surface irregularities. A conventional CMP device typically includes a polishing pad and a pad conditioner. The polishing pad is arranged on a polishing table, and includes a polishing surface for polishing a semiconductor wafer. A polishing slurry is dispensed onto the polishing pad through a tube. The pad conditioner includes a conditioning surface provided with a plurality of diamond grits or prisms to scrape against the polishing surface of the polishing pad. The pad conditioner functions to remove the polishing slurry that remained in the polishing pad so as to condition the polishing surface and recover the polishing characteristics of the polishing pad.

The pad conditioner may require frequent cleaning to ensure that it will not contaminate a semiconductor wafer in CMP process. Generally, after refurbishing a polishing pad, a pad conditioner is cleaned in a container, for example, an overflow tank, by continuously conveying a cleaning agent into the container. An excessive amount of the cleaning agent will likely to overflow the container as a result. However, parts of the cleaning agent may remain stagnant at the bottom of the container, which may result in deteriorating the cleaning performance and an unclean pad conditioner.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to a device and a method that obviate one or more of the problems due to limitations and disadvantages of the related art.

To achieve these and other advantages, and in accordance with the purpose of the invention as embodied and broadly described, there is provided a device for cleaning a pad conditioner that comprises a cleaning agent supply for providing a cleaning agent for cleaning a pad conditioner including a conditioning surface, a pad including an abrasive surface, and a pump rotating the pad with respect to the pad conditioner for rubbing the abrasive surface of the pad against the conditioning surface of the pad conditioner.

In one aspect, the pad further comprises a sponge.

In another aspect, the device further comprises a container for holding the pad conditioner and the pad.

Also in accordance with the present invention, there is provided a device for cleaning a pad conditioner that comprises an overflow tank for holding a pad conditioner having a conditioning surface provided with a plurality of grits, a cleaning agent supply for providing a cleaning agent to the overflow tank, a pad held in the overflow tank including an abrasive surface for contact with the conditioning surface of the pad conditioner, and a pump rotating the pad with respect to the pad conditioner for rubbing the abrasive surface of the pad against the conditioning surface of the pad conditioner.

Still in accordance with the present invention, there is provided a method for cleaning a pad conditioner that comprises the steps of providing a cleaning agent for cleaning a pad conditioner, reconditioning a polishing surface of a polishing pad using the pad conditioner, and rubbing a pad including an abrasive surface against a conditioning surface of the pad conditioner.

Additional objects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several embodiments of the invention and together with the description, serve to explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a device for cleaning a pad conditioner in semiconductor wafer planarization in accordance with one embodiment of the present invention; and

FIG. 2 is a flow diagram of a method for cleaning a pad conditioner in accordance with another embodiment of the present invention.

DESCRIPTION OF THE EMBODIMENTS

Reference will now be made in detail to the present embodiment of the invention, an example of which is illustrated in the accompanying drawing. Wherever possible, the same reference numbers will be used throughout the drawing to refer to the same or like parts.

FIG. 1 is a schematic diagram of a device 10 for cleaning a pad conditioner 12 in accordance with one embodiment of the present invention. Referring to FIG. 1, device 10 includes a cleaning agent supply 14, a pad 16, and a pump 18. Cleaning agent supply 14 provides a cleaning agent 14-2 to clean pad conditioner 12. In one embodiment, cleaning agent 14-2 includes deionized water. Pad conditioner 12 includes a conditioning surface 12-2 on which a plurality of diamond grits or prisms 12-4 are regularly arranged. Pad conditioner 12 is used to recondition a polishing surface of a polishing pad to an appropriate roughness. After reconditioning a polishing pad, foreign materials may adhere to conditioning surface 12-2 between grits 12-4.

Pad 16 includes an abrasive surface 16-2 for contact with conditioning surface 12-2 of pad conditioner 12. During a cleaning process, pad conditioner 16 is typically held by a robot arm (not shown). Pad 16 is supported and rotated by pump 18 to rub against conditioning surface 12-2 of pad conditioner 12 to remove foreign materials that remained between grits 12-4. In one embodiment, pad 16 includes a sponge that provides an abrasive action on conditioning surface 12-2. Pump 18 rotates pad 16 at approximately 60 revolutions per minute (“rpm”) for approximately 30 to 60 seconds.

Device 10 may further include a container 20 for holding pad conditioner 12, cleaning agent 14-2, and pad 16. In one embodiment, container 20 includes an overflow tank. Due to the rotation action of pump 18, cleaning agent 14-2 flowing below pad 16 is able to be pumped up to overflow container 20, and thus does not become stagnant at the bottom of container 20.

FIG. 2 is a flow diagram of a method for cleaning a pad conditioner 12 in accordance with another embodiment of the present invention. Referring to FIG. 2, cleaning agent 14-2, such as deionized water, is provided for cleaning pad conditioner 12 (step 21). The polishing surface of a polishing pad is reconditioned using pad conditioner 12 (step 22). The polishing surface is reconditioned to an appropriate roughness. Foreign materials may adhere to conditioning surface 12-2 between grits 12-4. Pad 16 is rubbed against conditioning surface 12-2 of pad conditioner 12 in order to remove the foreign materials remaining between grits 12-4 (step 23).

In one embodiment according to the present invention, the abrasive action on conditioning surface 12-2 is provided by pad 16 having a sponge. Pump 18 can rotate pad 16 up to 60 revolutions per minute (rpm) for 30 to 60 seconds in providing the abrasive action. By rotating pump 18, cleaning agent 14-2 is pumped to overflow container 20 in advantageously preventing stagnation of cleaning agent 14-2 (step 24).

Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims. 

1. A device for cleaning a pad conditioner comprising: a cleaning agent supply for providing a cleaning agent for cleaning a pad conditioner including a conditioning surface; a pad including an abrasive surface; and a pump rotating the pad with respect to the pad conditioner for rubbing the abrasive surface of the pad against the conditioning surface of the pad conditioner.
 2. The device of claim 1, the pad further comprising a sponge.
 3. The device of claim 1, the pad further comprising a disc shape.
 4. The device of claim 1, the pad further comprising a square shape.
 5. The device of claim 1 further comprising a container for holding the pad conditioner and the pad.
 6. The device of claim 1, the pump rotating at approximately 60 revolutions per minute (rpm).
 7. The device of claim 1, the cleaning agent further comprising deionized water.
 8. A device for cleaning a pad conditioner comprising: an overflow tank for holding a pad conditioner having a conditioning surface provided with a plurality of grits; a cleaning agent supply for providing a cleaning agent to the overflow tank; a pad held in the overflow tank including an abrasive surface for contact with the conditioning surface of the pad conditioner; and a pump rotating the pad with respect to the pad conditioner for rubbing the abrasive surface of the pad against the conditioning surface of the pad conditioner.
 9. The device of claim 8 wherein an abrasive action of the pad results in removal of foreign materials remaining between the plurality of grits of the pad conditioner.
 10. The device of claim 8, the cleaning agent further comprising deionized water.
 11. The device of claim 8, the abrasive surface further comprising a sponge surface.
 12. The device of claim 8 wherein the cleaning agent is pumped to overflow the overflow tank in preventing stagnation of the cleaning agent.
 13. A method for cleaning a pad conditioner comprising the steps of: providing a cleaning agent for cleaning a pad conditioner; reconditioning a polishing surface of a polishing pad using the pad conditioner; and rubbing a pad including an abrasive surface against a conditioning surface of the pad conditioner.
 14. The method of claim 13 further comprising the step of rotating the pad with respect to the pad conditioner using a pump such that the abrasive surface of the pad rubs against the conditioning surface of the pad conditioner and removes foreign materials remaining between a plurality of grits of the pad conditioner.
 15. The method of claim 13 wherein an abrasive action against the conditioning surface of the pad conditioner is provided by a sponge in the pad.
 16. The method of claim 13 wherein the pad is in a disc shape.
 17. The method of claim 13 wherein the pad is in a square shape.
 18. The method of claim 13 wherein the pad conditioner is cleaned using deionized water. 